stylolite

a small, columnlike formation in a rock deposit, having grooved or scratched sides and usually composed of limestone

Origin of stylolite

stylo- from Classical Greek stylos (see stylite) + -lite

stylolite

noun

A secondary structure found along contacting surfaces of adjacent calcareous rock layers, the contact zone appearing in cross section as a series of jagged interlocking up-and-down projections that resemble a suture or the tracing of a stylus.